Singular 7-manifolds with G(2) holonomy and intersecting 6-branes

A 7-manifold with G(2) holonomy can be constructed as a R-3 bundle over a quaternionic space. We consider a quaternionic base space which is singular and its metric depends on three parameters, where one of them corresponds to an interpolation between S-4 and CP2 or its non-compact analogs. This 4d Einstein space has four isometrics and the fixed point set of a generic Killing vector is discussed. When embedded into M-theory the compactification over a given Killing vector gives intersecting 6-branes as IIA configuration and we argue that membrane instantons may resolve the curvature singularit